2022/23 University of Hertfordshire Life & Medical Sciences Past Paper PDF

EXAMPLE PAPER UNIVERSITY OF HERTFORDSHIRE Candidates please enter your SRN in these boxes Academic year: 2022/23 Exam Session: Example Paper School/Dept: Life & Medical Sciences / Clinical, Pharmaceutical and Biological Sciences Mo...

EXAMPLE PAPER UNIVERSITY OF HERTFORDSHIRE Candidates please enter your SRN in these boxes Academic year: 2022/23 Exam Session: Example Paper School/Dept: Life & Medical Sciences / Clinical, Pharmaceutical and Biological Sciences Module code: 4LMS0154 & 4LMS0166 Module title: Core Biochemistry Duration of Exam: Two hours THE FOLLOWING IS PROVIDED FOR THIS EXAMINATION: ONE MCQ answer sheet. ONE answer book. Continuation answer sheets can be requested from an invigilator. Ensure you write your SRN on any sheets which are to be handed in. INSTRUCTIONS TO CANDIDATES: This paper consists of 27 questions (23 in this example) on 8 pages including this page. Please answer ALL the questions in Section A. Section A carries 50% % of the marks. For Section A mark the ONE, most accurate and complete, answer to each question against the corresponding number on the MCQ ANSWER SHEET by filling in the bubble. For example: if you think the answer to question 8 is c mark your answer as follows: 8 a b c d e Use an HB pencil and make your marks like this NOT a  or X. Erase all errors thoroughly. If you choose anything other than the best option, or if you choose more than one option for a problem, you will receive NO marks for that question. You are advised to spend no more than 60 minutes on Section A. Please answer 1 out of 3 questions in Section B. Section B carries 50 % of the marks. For Section B you must provide the answer in the answer book You are advised to spend no more than 15 minutes preparation and 45 minutes writing on Section B, in total 60 minutes. University approved calculators allowed? YES Are question papers allowed to be taken at the end of the exam? NO Note that this an example exam paper with a reduced number of MCQs (20). Page 1 of 8 EXAMPLE PAPER SECTION A This section contains 24 questions (20 questions in this example). You are advised to spend no more than SIXTY minutes on this section. Mark the ONE most accurate and complete answer to each question against the corresponding number on the MCQ answer sheet. Answer ALL questions. This section contributes 50% of the marks. 1) If ΔG0’ for a chemical reaction is -220 J mol-1, what is the equilibrium constant K? (ΔG = -RT ln K, R = 8.314 J K-1 mol-1, T=298.15 K) a) 0.0887 b) 1.09 c) 220 d) 8.314 e) 0.019 2) An inhibitor I binds to an enzyme E according to the reaction scheme: The rate law for this elementary reaction is given by: a) d[EI]/dt = k1 [I][E] b) d[EI]/dt = k-1 [EI] - k1 [EI] c) d[EI]/dt = k1 [EI] d) d[EI]/dt = (k1 + k-1 ) [I] [E] e) d[EI]/dt = k1 [I][E] – k-1 [EI] 3) For the enzyme alkaline phosphatase the maximal initial reaction rate vmax was determined as 12.5 μmol L-1 s-1. The concentration of active enzyme was determined as 0.2 μmol L-1. How many substrate molecules are turned over by the enzyme? a) 62.5 s-1 b) 2.5 s-1 c) 12.5 s-1 d) 6.25 s-1 e) 125 s-1 Page 2 of 8 EXAMPLE PAPER 4) Regarding the reaction of pyruvic acid with water, which of the following statements is NOT correct ? a) In the forward reaction pyruvic acid donates a proton to water. b) In the forward reaction water acts as a base. c) In the backward reaction pyruvate acts as an acid. d) In the backward reaction pyruvate accepts a proton. e) In reality, the protonated water is not accurately described by “H3O+“. 5) Glycolysis is upregulated by increased levels of: a) ATP b) AMP c) ADP d) Citrate e) Alanine 6) The process of gluconeogenesis not only clears cells of some molecular debris but can also provide glucose for these cells that need a constant supply: a) Kidney, liver, and aerobic muscle. b) Brain, red blood cells, anaerobic muscle, and lactating mammary. c) Heart, liver, and pancreas. d) Tissue that is rapidly oxidizing lipids. e) Tissue in which glycolysis is occurring rapidly. 7) Which of the following enzyme is responsible for glycogen breakdown? a) Glycogen phosphorylase b) Glycogen phosphatase c) Glycogen hydrolase d) Glycogen hydrolase e) Hexokinase Page 3 of 8 EXAMPLE PAPER 8) The following radioactive decay is observed: 228 228 Ra Th 88 90 The isotope has decayed by: a) 1 alpha particle + 1 beta particle b) 2 alpha particles c) 2 beta particles d) 1 gamma wave e) none of the options are correct. 9) Radioactivity can be detected via: a) ionisation of gases in a Geiger counter b) excitation of phosphors in a Geiger counter c) blackening of photographic film in a Geiger counter d) ionisation of gases in a Scintillation Counter e) excitation of phosphors in a Dosimeter. 10) A patient is given a radionuclide for diagnostic purposes. The radionuclide has a half- life of 6 hours. After 12 hours the amount left is 10mCi. How much of the radionuclide was given to the patient? a) 10 mCi b) 20 mCi c) 5 mCi d) 40 mCi e) 100 mCi 11) The products of the citric acid/Krebs’/TCA cycle include: a) NAD+ and FADH b) NADH and FADH c) NADH and FADH2 d) NADH and FAD e) citric acid and O2 Page 4 of 8 EXAMPLE PAPER 12) In the initial step of the citric acid/Krebs’/TCA cycle: a) acetyl CoA combines with malate to form oxaloacetate b) acetyl CoA combines with oxaloacetate to form citrate c) acetyl CoA combines with citrate to form isocitrate d) pyruvate combines with citrate to form isocitrate e) pyruvate combines with oxaloacetate to form citrate. 13) What is the main purpose of oxidative phosphorylation? a) The oxidation of glucose to CO2 and H2O. b) The production of reduced coenzyme Q for a healthy organism. c) The maintenance of the protonmotive force. d) The oxidation of NADH and FADH2 in small steps for maximum ATP production. e) The elimination of free oxygen as it is dangerous. 14) If the ATP synthase stopped working during oxidative phosphorylation, what would happen? a) The electrons transport chain would show very high activity. b) The electron transport chain would show very low activity. c) There would be no ATP formation due to substrate phosphorylation. d) NADH2 would form ATP directly. e) The protonmotive force would be reduced to zero. Page 5 of 8 EXAMPLE PAPER Questions 15-19 refer to to the β-oxidation spiral shown in Figure 1 below Figure 1: the β-oxidation spiral 15) What is metabolite B? a) ATP b) H2O c) NADH d) FADH2 e) Acetyl coenzyme A 16) Which type of reaction occurs in reaction ONE? a) Isomerisation b) Reduction c) Hydrolysis d) Oxidation e) Thiolysis Page 6 of 8 EXAMPLE PAPER 17) Which type of reaction occurs in reaction TWO? a) Oxidation b) Hydrolysis c) Isomeration d) Reduction e) Thiolysis 18) What is metabolice C? a) ATP b) NAD+ c) FAD d) FADH2 e) H2O 19) Which type of reaction occurs in reaction FOUR ? a) Oxidation b) Hydrolysis c) Isomeration d) Reduction e) Thiolysis 20) Which of the following statements about ketone bodies is TRUE? a) Ketone bodies are generated from two molecules of acetyl CoA. b) Ketone bodies are synthesised in the brain. c) The conversion of acetoacetate to acetone produces NAD+. d) Ketone bodies can be used by red blood cells as a source of energy. e) The conversion of acetoacetate to 3-hydroxybutyrate is irreversible. Page 7 of 8 EXAMPLE PAPER SECTION B Answer ONE out of three questions. All questions are weighted equally. You are advised to spent no more than 60 minutes on this section. This section contributes 50% of the marks 1) Explain in words and with equations how the relationship between ΔG and the mass action ratio Γ, namely ΔG = ΔG0’ + RT ln Γ leads to the important equation: ΔG0’ = -RT ln K (with K: equilibrium constant, R = 8.314 J K-1 mol-1, T: temperature in Kelvin). 2) Outline the process of gluconeogenesis by describing the reactions of this pathway and discussing its regulation. 3) Figure 2 below shows the structure of a protein formed of two subunits. Figure 2: The structure of a protein formed of two subunits, each subunit is shown in a different colur. Explain the description of protein structures at the level of quaternary, tertiary, secondary and primary structure AND indicate what stablises protein structures at those levels. Page 8 of 8